$OpenBSD: vmt.4,v 1.4 2010/10/26 05:07:31 jmc Exp $
Copyright (c) 2008 Marco Peereboom <marco@openbsd.org>
Text was heavily borrowed from the IPMI spec V1.5
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.Dd October 6, 2013 .Dt VMT 4 x86 .Os .Sh NAME .Nm vmt .Nd VMware Tools driver .Sh SYNOPSIS .Cd "vmt0 at cpu0" .Sh DESCRIPTION The .Nm driver is a kernel level implementation of VMware Tools. VMware Tools are intended to provide better support for operating systems running inside virtual machines.
p
.Nm
handles shutdown, reboot, resume requests from the host by sending
events using
.Xr sysmon_pswitch 9
of type PSWITCH_TYPE_POWER, PSWITCH_TYPE_RESET, and PSWITCH_TYPE_SLEEP that
can be handled by
.Xr powerd 8 .
.Nm
will log notifications that the guest has been suspended or resumed by the
host.
It also provides access to the host machine's clock as a timedelta sensor.
p
.Nm
reports the guest's hostname and first non-loopback IP address to the host.
.Ss Clock synchronization
The
.Nm
driver synchronizes the virtual machine's clock with the host clock in the
following situations:
l -bullet t When the virtual machine resumes after having been suspended.
t Periodically with the interval indicated by the
.Va machdep.vmt0.clock_sync.period
.Xr sysctl 8
variable.
This is done so that the virtual machine can keep its clock synchronized
when the host is suspended, because in this case the
.Nm
driver receives no notification of such an event.
Setting this tunable to zero disables clock synchronization.
.El
.Sh SEE ALSO
.Xr cpu 4 ,
.Xr powerd 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 4.4
and was then ported to
.Nx 6.0 .
.Sh AUTHORS
The
.Nm
driver was written by
.An David Gwynne Aq Mt dlg@openbsd.org .